1. Field of the Invention
The present invention relates to a method and apparatus for forming a silicon film.
2. Description of the Related Art
Manufacturing processes of a semiconductor device or the like include a process of forming a trench and a groove having a hole shape (contact hole) in an interlayer insulation film on a silicon substrate, and forming an electrode by embedding a silicon film (Si film), such as an impurity-doped polysilicon film or amorphous film.
As such a process, for example, Patent Document 1 discloses a method of forming a contact hole in an interlayer insulation film on a silicon substrate, forming a polysilicon film by a chemical vapor deposition (CVD) method, slightly etching the polysilicon film, and then again forming the polysilicon film.
However, according to such a method of forming a Si film, a surface roughness of the Si film may be deteriorated due to etching when an impurity-doped polysilicon film, for example, a P-doped Si film, is used as the Si film. This is assumed to be caused because the etching is performed from a P-site in the P-doped Si film. Thus, if the P-doped Si film is additionally formed on the P-doped Si film having the deteriorated surface roughness, a void or seam is easily generated.
(Patent Document 1) Japanese Laid-Open Patent Publication No. hei 10-321556